Calcium silicate hydrate (C–S–H) is the main binding product of ordinary Portland concrete (OPC). Unfortunately, OPC production generates ∼5% of all anthropomorphic CO₂. Among the most promising green alternatives, magnesium silicate hydrate (M–S–H) is a colloidal gel equivalent to C–S–H which exhibits weaker mechanical properties. Here we investigated the effect of the inclusion of aluminosilicate nanoclays (HNTs) on the microstructure of the silicate hydrate gels as a strategy to ultimately improve their mechanical properties. The microstructure of C–S–H and M–S–H gels synthesized with and without carboxylic or polycarboxylic functionalised HNTs (HNT–COOH, HNT–PAA) was investigated by a multi-technique approach including small- and wide-angle X-ray scattering (SWAXS) and scanning electron microscopy (SEM). The results indicate that, during C–S–H formation in solution, HNTs decrease the size of the disk-like globules with little influence on the spacing of calcium silicate layers. In the case of M–S–H, the presence of functionalised HNTs has a reduced effect on the hydrate structure as a result of the weaker interaction of the carboxylic moieties with Mg²⁺ ions. SEM investigation on the synthesized composites shows that HNT–PAA are better included in the hydration products. Moreover, in the proximity of the PAA functionalised surfaces, less extended aggregates are formed. The morphology at the micron scale for M–S–H and C–S–H with HNT–COOH is conserved.

中文翻译：

---

功能化纳米粘土作为钙和镁硅酸盐水合物的微结构改性剂

水合硅酸钙（C–S–H）是普通波特兰混凝土（OPC）的主要粘结产品。不幸的是，OPC的产生会产生约5％的拟人CO ₂。在最有希望的绿色替代品中，水合硅酸镁（M–S–H）是等效于C–S–H的胶体凝胶，但其机械性能较弱。在这里，我们研究了硅铝酸盐纳米粘土（HNTs）的掺入对硅酸盐水合物凝胶微观结构的影响，以此作为最终改善其机械性能的策略。用多种技术方法研究了有无羧基或多羧基官能化HNT（HNT-COOH，HNT-PAA）合成的C–S–H和MS–H凝胶的微观结构。射线散射（SWAXS）和扫描电子显微镜（SEM）。结果表明，在溶液中C–S–H形成过程中，HNTs减小了盘状小球的大小，而对硅酸钙层的间距影响很小。对于M–S–H，²⁺离子。SEM对合成复合材料的研究表明，HNT-PAA更好地包含在水合产物中。而且，在PAA官能化表面附近，形成较少延伸的聚集体。使用HNT-COOH的M–S–H和C–S–H的微米级形态是保守的。